Joist construction



Nova L QBZ; H, F.' YQUN@ 39%@59333 JOIST CONSTRUCTION Filed Sept. 22. 1930 NVENTOR Patented Nov. 1, 1932 UNITED STATES PATENT vOFFICE:

HOWARD F. YOUNG, or `imnmmzoo, MIcHIGAN, AssIGuon` F ONE-HALF To LEON-1E s.

YOUNG, or mLAmzoo, MICHIGAN JOIST CONSTRUCTION Application led September 22, 1930. Serial No. 483,439.

This invention relates to detailed improvements of the structure ap 'caring in my patent application Serial No. 4 2,828, filed August 4, 1930. Y

5' The objects of this inventionl are:

First, to provide improvements in details of construction of the top cord of the joist, particularly as to the details of the steel member. y

Second, to provide such a steel member with improved construction of shear-resisting and fabric-engaging prongs.

Third, to provide such a structure which is composite in that the prongs are formed on an added bonding strip welded or otherwise secured to the head of the joist.

Fourth, to provide an improved floorconstruction containing these features.

Further objects, and objects pertaining to details and economies will definitely appear from the description to follow.

Preferred embodiments of my invention are illustrated in the accompanying drawing, in which:

Fig. 1 shows the head o fa joist with the preferred form of my improved prong' structure.

Fig. 2 is a modified form in which the prongs are struck up from the anges at each side of the head of a metal j oist. s

Fig. 3 is a plan view showing the disposif tion and arrangement of rib lath in connection with the joist. j

Fig. 4 is a detail cross section through the head of a j oist and the superposed floor slab.

Fig. 5 is a detail of my improvement with a modified form of prong.

Fig. 6 is a plan view of the blank strip showing the method of forming the prongs as appears in Fig; 5.

Fig. 7 is a ydetail plan view similar to Fig. 6 where square prongs are formedon Ythe added strip. A

The parts will be identified by their numerals of reference which are the same in all views.

1 is a metal ioor joist, the head only of which shown. 2 is the supplementary bonding strip on which are formed the prongs 3. The bonding strip is preferably Vspotwelded on tothe head of the joist 1 as seen in Fig. 1. It maybe secured in any way. The prongs are dove-tailed in form, being struck up from the margins of the bonding strip, or in the alternative structure as seen in Fig. 2, from vthe margins of the projecting flange of the head of the metal joist. These are formed by an angular cut in from the margin and a second cut connectingl therewith to form a dove-tail construction when the prongs are bent out at substantially right an les. l

e prongs of this shape readily penetrate mesh lath between the ribs or the body of Steeltex which is a lath having paper back with metal reinforce. In fact, any lath structure containing metal can be utilized with the structure and will be retained by the peculiar .shape of the prongs.V The prongs project through the mesh to interlock with the concrete slab to aii'ord resistance to horizontal shear or slippage between the slab and the joist, incorporating the two as a composite concrete and steel T beam so as to utilize the concrete slab itself for compression stresses in the structure.

rlhe preferred form of the prongs is seen in Fig. l Where they are shown yin the preferred construction. In Fig. 2 they are -shown in the alternative, lformed from the flanges forming the head of the metal j oist.

In Fig. 5 a modified form is shown with comparatively long lingers which are capable of insertion through the 'mesh and of being bent down. In Fig. 7 4 I illustrate the prongs as rectangular in contour where they would have straight sharp edges which would assist in shearing the mesh or web of lath when l placing vthe same. l

Any form of prong could be made use of in connection-with the supplementary bonding strip. The flanges might also be vari- Aously cut to make prongs. The joists, in-

stead of being simple T joists, may be' made up of plates and angle iianges of other form to which the supplementary bonding strip. may be secured, or on which prongs may be formed. The supplementary bonding strip Vmight be secured to a straight beam or bar.

The usual lath attaching clips may be used.

The invention is es ecially well adapted to a joist construction, ut is also available for girders or beams of any description where a concrete slab or structure is bonded to the 5 head of the beam.

I desire to claim m invention broadly and also in the specific orms illustrated.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. The combination with a metal joist having a T head, a supplementary bonding strip having dove-tail shaped angular prongs struck up therefrom welded to the said joist head, a rib lath disposed across the said joists with its mesh engaging the said prongs,

and a concrete slab incorporating the said lath, prongs and head into a unitary bonded structure, utilizing the slab as a compression member.

2. The combination with a metal joist having a T head, a supplementary bonding strip having dove-tail shaped angular prongs struck up therefrom welded to the said joist S5 head, a lath disposed across the said joists with its mesh engaging the said pron s, and a concrete slab incorporating the sai lath,

prongs and head into a unitary bonded structure utilizing the slab as a compression mem- 30 ber.

3. The combination with a metal j oist having a T head having dove-tail shaped an lar prongs struck up therefrom, a lath posed across the said joists with its mesh y85 engaging the said pron s, and a concrete slab incorporating the said ath, prongs and head into a unitary bonded structure utilizing the slab as a compression member.

4. The combination with a metal joist hav- 4o ing a T head having dove-tail shaped angular prongs struck up therefrom, and a concrete slab incorporating the said prongs and head into a unitary bonded structure utilizing the slab as a compression member.

5. The combination with a metal joist having a T head, and a supplementary bonding strip having dove-tail shaped angu ar prongs lsltruzk up therefrom welded to the said joist ea In witness whereof I have hereunto set my hand.

HOWARD F. YOUNG. 

